Skirting arrangements for ground-effect machines

ABSTRACT

The present invention relates to improvements in ground-effect machines of the kind comprising a structure located opposite a bearing surface at a variable distance therefrom, the skirting arrangements which delimit the plenum chamber being associated with means which sense the height of the leakage gap between bearing surface and skirt edge in order to control the raising and lowering of said skirting arrangement as a function of the lowering and raising of the ground-effect machine, the purpose being to prevent premature wear of said skirting edge.

United States Patent [72] Inventor S m m MM m MA a m m m f u mm mm, mm

21 AppLNo. 813,659

[22] Filed Apr. 4, 1969 [45] Patented May 11, 1971 [73] Assignee SocieteDe LAerotrain Paris, France Apr. 5, 1968 France Primary Examiner-A. Harry Levy Attorney-Stevens, Davis, Miller and Mosher 32 Priority ABSTRACT: The present invention relates to improvements in ground-effect machines of the kind comprising a structure located opposite a bearing surface at a variable distance therefrom, the skirting arrangements which delimit the plenum chamber being associated with means which sense the height of the leakage gap between bearing surface and skirt edge in order to control the raising and lowering of said skirting arrangement as a function of the lowering and raising of the ground-effect machine, the purpose being to prevent premama flwnfl D W 16,81 m G M n R m m G i m m mew mm m mm SEH U. hm N H m w w. 55

mature wear of said skirting edge.

PATENTED MAY] 1 I97! sum 2 [1F 3 PATENTEB MAY] 1 197: 3,578,099

SHEET 3 BF 3 T a x SKIR'IING ARRANGEMENTS FOR GROUND-EFFECT MACHINES The present invention relates .to a ground-effect of the kind comprising'a structure located opposite a bearing surface at a variable distance therefrom, and a lateral confining arrangement movable in relation to said structure and delimiting an enclosure of the plenum chamber kind designed, in cooperation with said bearing surface, to define at least one fluid cushion, said confining arrangement comprising a terminal part having a free end adjacent the bearing surface and separated therefrom by a certain interval. The height of said interval or gap, referred to as the leakage height should fundamentally remain as small as possible for reasons connected with the general efficiency of the machine.

An inherent problem in the use of ground-effect machines of the aforesaid kind is that of protecting the walls of the lateral confining arrangement, or skirt, more particularly their free ends, in circumstances where, after the deliberate or inadvertent cessation of the supply to the cushions of pressurized fluid, that is to say after the cessation of the ground effect and a corresponding sinking of the machine, the latter is constrained nevertheless to move in relation to the bearing surface. Because to the small height of the leakage gap, the free ends of the'confining walls or skirts, then come into contact with the bearing surface, often rough, and are prematurely worn as a consequence of the friction which this involves. This problem relates in particular to certain kinds of movable bodies or like vehicles forming part of a mechanical conveyor transportation system, for example of the belt conveyor kind, such as that forming the subject of the Fat. application Ser. No. 813,597 filed Apr. 4, I969 by the present applicant and entitled Improvements In Or Relating To Transportation Systems, which movable bodies or vehicles can be carried alternatively by ground-effect and by mechanical conveyors.

When such a vehicle is resting upon the mechanical conveyor, its lift cushion or cushions is or are not supplied with pressurized fluid, so that the vehicle experiences a relative sinking movement which may mean that the free ends of the skirting arrangements come into contact with the bearing surface opposite them, which bearing surface may be stationary in relation to the moving conveyor which is carrying the vehicle.

A similar problem arises when certain kinds of ground-effect vehicles are braked, when said braking is produced by the cessation of the fluid supply to said lift cushions and a corresponding sinking on the part of the vehicle, which vehicle may be equipped with brake shoes designed to cooperate with the bearing surface.

It is the object of the present invention to resolve the general problem hereinbefore defined, namely that of protecting the walls of skirts of the confining arrangement when the supply fluid to the cushions is cut off.

In accordance with the invention, means responding to the distance between the structure and the bearing surface and provided in order to displace the terminal part of the lateral confining arrangement in relation to the structure and to the bearing surface in a direction such that the height of the leakage gap increases when the distance between the structure and the bearing surface diminishes, and conversely.

In accordance with a preferred embodiment the lateral confining arrangement comprises at least one deformable wall and the means responding to the distance between the structure and the bearing surface comprise a reference element fixed to said deformable wall and movable in relation to said structure in a substantially normal direction to the bearing surface, said reference element being designed to come into contact with said bearing surface. Said responding means will also preferably comprise a linkage cooperating with the structure and connected to a portion of the deformable wall defined between the free end of the lateral confining arrangement and the zone of attachment of the reference element to said deformable wall, in such fashion that said free end is displaced when the distance between said structure and said reference element varies.

the deformable wall and bearing at its other end against the said structure, said end advantageously exhibiting a substantially spherical tip or like roller in order to reduce the friction with the structure.

In accordance with another feature of the invention, elastic means are provided in order to return the deformable wall in the direction corresponding to closer approach of the terminal portion of the lateral confining device towards the bearing surface. To this end, a part of the deformable wall may itself have an elastic structure. I

In accordance with another feature of the invention, the reference element comprises a runner designed to rest upon a bearing surface (for example, the ground, a prepared track or again a mechanical conveyor, for example a belt conveyor, of the general kind hereinbefore referred to), said runner having an extension upon which the structure can rest when said runner itself rests on the bearing surface. A stop integral with the structure can likewise be provided in order to limit to a predetermined maximum value, the distance between the structure and the runner. The latter may also be lifted when the machine is in the ground-effect configuration.

In accordance with another feature of the invention, the machine comprises, additionally, at least one brakeshoe located opposite the bearing surface and designed to move into contact therewith, said shoe being fixed to the structure through the medium of an elastic arrangement such as a flexible strip. The stiffness of the latter may be designed so that when the ground-effect disappears, the major part of the weight of the machine is transmitted to the bearing surface by said shoe.

The ensuing description which relates to the attached drawings, given by way of nonlimitative examples, will indicate how the invention may be put into effect.

FIG. 1 is a schematic elevational illustration of a transportation system using movable bodies or like vehicles which are supported and propelled by a mechanical conveyor, certain ones, at least, of said bodies or vehicles being equipped with an enclosure capable of delimiting a fluid cushion through the agency of a retractable confining arrangement or skirt, in accordance with the invention;

FIGS. 2 and 3 are sectional views, on a slightly larger scale, taken respectively on the lines 11- and III-III of FIG. 1, through the transportation system of FIG. 1;

FIG. 4 is a sectional view, on a larger scale, showing the retractable confining arrangement in the operative position, that is to say when fed with pressurized fluid;

FIG. 5 is a view similar to that of FIG. 4, showing the same arrangement in the retracted position, the supply of pressurized fluid having been cut off.

In order to illustrate the invention, the above-enumerated example of movable bodies or like vehicles forming part of a mechanical conveyor transportation system, for example a belt conveyor arrangement, has been chosen, although it is obvious that the invention extends equally to any machine capable of operating permanently or intermittently in accordance with the ground-effect principle.

In FIGS. 1, 2 and 3, the references C designate mechanical conveyors forming part of a transportation system similar to that forming the object of the patent application hereinbefore referred to', each of these conveyors comprises tow endless belts 1, each having a top working run la upon which a movable body, such as a vehicle or cabin M, can rest through the medium of runners 2 and shoes 23. The two belts are driven by a drive shaft 3 and rest on rollers or the like 4 which are located in recesses 5 in a plate or panel 6 covering a space 7 which communicates through a piping arrangement 8 with a fluid pressure source.

The plate or panel 6 comprises feed passages in the form of 5 directional nozzles 9 capable of being closed off by clackvalves 10 carried by a linkage 11 articulated at 12 to the plate 6 and subjected to the action of a spring 13. An arm 14 projecting in sealed fashion outside said space, terminates in an element 15 designed to cooperate with a lever 16 provided for the use of the person riding in the vehicle or cabin.

The space 7 is delimited peripherally by a deformable wall 17 fixed in sealed fashion to the plate or panel 6. This plate or panel is articulated at 18 about a fixed axis substantially longitudinally disposed and carried by a prepared track 19 in which the conveyors C are mounted. The reference 20 marks a stop.

The vehicle or cabin M is equipped with a structure 21 at the bottom end of which an enclosure of the plenum chamber kind is connected, so that said vehicle can, if required, operate as a ground-effect machine.

This enclosure is delimited by a lateral confining or skirting arrangement 22, comprising retractable walls which more precisely constitute the object of the present invention. The reference 23 designates brakeshoes fixed to the base of the structure through the medium of elastic strips 24.

FIG. 2 illustrates the vehicle M carried by the runners 2 and the shoes 23, on the moving belts 1. It will be appreciated that in the absence of any ground-effect the confining arrangement 22 is in the retracted position its free end being spaced away from the bearing surface constituted, in the present instance, by the top face 6a of the plate or panel 6, this in order to avoid any premature wear by contact with said face. The spacing away of the extremity 26a (see FIG. 5) in nevertheless compatible with the eventual development of a pressurized fluid cushion.

FIG. 3 illustrates the vehicle M in the ground-effect configuration. In order to bring about this state, the user of the vehicle operates the lever 16 which bears against the arm 14, in order to bring about the opening of the clack-valves 10 which were hitherto kept closed by the action of the spring 13 on the linkage ]1. The pressurized fluid stored in the space 7 then escapes across the directional noules 9 and creates a pressurized fluid cushion beneath the vehicle which lifts said vehicle away from the belts l.

correspondingly, the pressure prevailing in the space 7 drops to a lower value thus causing the plate or panel 6 to sink and pivot about its hinge 18 until it hits the stop 20. The vehicle can then slide laterally over said plate or panel aided by the effect of the directional nozzles, and thus transfer onto a prepared area 25. The latter will advantageously likewise be supplied with pressurized fluid, this by automatic means responsive to the passage of the vehicle, and can be arranged to direct the vehicle towards a parking or marshalling area. Once it has arrived at its final destination, the vehicle is braked by the cutting off of the supply of fluid to the cushions. It will be noted that in the ground-effect configuration, the runners 2 and the shoes 23 are lifted whilst the free end of the confining device 22 is moved close to the top or bearing face 60 of the plate or panel in order to define in relation thereto a reduced leakage gap.

FIGS. 4 and 5 provide a more detailed illustration of the retractable confining or skirt arrangement in accordance with the invention, in the two configurations hereinbefore enumerated. This arrangement comprises lips 26 fixed to elastic walls 27, and flexible walls 28 fixed in a substantially sealed fashion to the structure 21. The lips have a free end opposite the bearing surface 1a 6a. in order to determine in relation thereto a leakage gap of height h (see FIG. 4). The walls 27 and 28 are secured to one another in substantially sealed fashion by means of a peripheral frame 29. The latter carries a shock absorber 30 upon which, at intervals, there are located studs 31, preferably of elastic material such as rubber,

designed to limit the lateral deploying movement between confining arrangement 22 and structure 21.

In accordance with the invention, means which respond to the distance between the structure 21 and the bearing surface 1a -6a, are provided. These means comprise arrangements which are sensitive to the relative position of the structure 21 and at least one reference element 2 carried by the confining arrangement, and they enable that latter to be deformed or displaced in such a manner that the height h hereinbefore defined varies as a function of said relative position. In the particular case illustrated, the reference elements are constituted by the runners 2 upon which the structure 21 can rest. These runners, which have extensions 2a upon which the structure 21 can rest, are fixed to the confining arrangement in the intermediate zone thereof defined by the frame 29, and are movable in relation to the structure 21 in a direction substantially normal to the bearing surface, the relative displacement of the structure 21 and of the runners 2 being limited by stops 32.

A linkage 33 provides a kinematic link between the structure 21 and that part of the confining arrangement which is defined between the intermediate zone (itself defined hereinbefore) and the free end 26a. It will advantageously comprise a lever fixed at one of its ends 330, to the elastic wall 27, and bearing at its other end 33b against that face 21a of the structure which faces the bearing surface 10 6a. The effect of the elasticity of the wall 27 is to elastically bias it in the direction corresponding to approach of the free end 26a towards said bearing surface, the end 33b of the lever being applied against the face 21a of the structure 21. Equally, however, for this purpose an auxiliary elastic return device could be provided, such as a spring arrangement. Preferably, the end 33b of the linkage 33 will have a substantially spherical tip or a roller, cooperating with a mating surface 34 of low coefficient of friction.

In operation, when the cushion is supplied with pressurized fluid and the vehicle is therefore in the ground-effect configuration, the structure 21 is spaced away from the supporting surface 1a --6a; this condition being shown in FIG. 4. Lifted by the stops 32, the runners 2 are maintained at a certain distance above the bearing surface la 6a, as are the brakeshoes 23. The linkage 33 now occupies a position such that the leakage height has the reduced valve h necessary for efficient operation of the system.

When the fluid cushion is cut off, the vehicle sinks and the structure 21 approaches the bearing surface la 6a. During a first phase of this movement, the shoes 21 and the runners 2 move at the same time as the structure 21 until they come into contact (first the shoes, and then the runners), with the bearing surface, whereas, during a second phase of the movement, the structure 21 continues its displacement alone in order finally to come to rest upon the extensions 2a of the runners 2. During this second phase the linkage 33 displaces until it occupies the position shown in FIG. 5, forcing the lips 26 away from the bearing surface 1a6a and, consequently, increasing the gap separating said bearing surface and the free end 26a. The latter is thus protected.

It will be seen that as soon as the runners 2 are in contact with the bearing surface, they constitute the aforedescribed fixed reference elements in relation to which it is possible to detect the position of the structure 21.

FIG. 5 relates to the case of a vehicle resting upon a bearing surface 1a which is moving, e.g. the surface of a conveyor belt. The shoes 23 then rest upon the belt without having any braking effect. If, on the other hand, the bearing surface is fixed, then the vehicle is braked by the shoes 23. The stiffness of the elastic strips 24 will preferably be contrived so that the major part of the weight of the vehicle is transmitted to the bearing surface through the medium of said shoes 23 with the effect that the braking effort exerted by the runners 2,'and consequently the wear to which these runners are subjected, is reduced to a minumum.

structure and delimiting a plenum chamber designed in cooperation with said bearing surface to confine at least one cushion of pressurized fluid for supporting said machine free of said bearing surface, said lateral confining arrangement comprising a terminal part with a free end adjacent the bearing surface and separated therefrom by a certain interval; means responding to the distance between the structure and the bearing surface for displacing the terminal part of the lateral confining arrangement in relation to said structure and to saidbearing surface, in a direction such that the said interval increases when said distance reduces, and conversely. V

2. A machine as claimed in claim 1, wherein the lateral confining arrangement comprises at least one deformable wall,

and wherein the means responding to the distance between the structure and the bearing surface comprise a reference element fixed to said deformable wall and movable in relation to said structure in a direction substantially normal to the bearing surface, said referenceelementbeing adapted to come into contact with said heating surface when said machine rests directly on said bearing surface.

3. A machine as claimed in claim 2, wherein said responding means further comprises a linkage, and means on said linkage cooperating with the structure and connected to a portion of the deformable wall which is defined between the free end of said lateral confining arrangement and the zone of attachment of the reference element to said deformable wall, whereby said free end is displaced when the distance between said" at the other end of said lever bearing against said structure.

5. A machine as claimed in claim 4, wherein the end of the lever which bears against the structureconiprises' a substantially spherical roller. v

6. A machine as, claimed in claim 3, further comprising elastic means for returning the deformable wall in the direction corresponding to approach of the free end of said lateral confining arrangement towards said bearing surface.

7. A machine as claimed in claim 6, wherein said elastic means comprise a portion of said deformable wall.

8. A machine as claimed in claim 2, wherein the reference element comprises a runner adapted to rest upon the bearing surface, said runner having an extension upon which the structure can rest when said runner itself rests upon the bearing surface. A

9. A machine as claimed in claim 8, further comprising a stopintegral with the structure, said stop including means to limit to a predetermined maximum value the distance between said structure and said runner when said machine is supported by said fluid cushion.

10. A machine as claimed in claim 1, further comprising at least one brakeshoe located opposite the bearing surface, said brake shoe including means coming into contact with said bearing surface when said distance is reduced, an elastic means, and means securing said elastic means to said shoe and to the structure.

11. A machine as claimed in claim 2, wherein the reference element comprises a runner having an underface adapted to rest upon the bearing surface, said machine further comprising a stop integral with the structure, said stop including means to limit to a predetermined maximum valve the distance between said structure and said runner when said machine is supported on said fluid cushion, and at least one brakeshoe having an underface located op osite the bearing surface and designed to come into contact t erewith, wherein the distance between the underface of the brakeshoe and the bearing surface is smaller than the distance between the underface of the runner and said bearing surface, when said runner bears against said stop. 

1. A ground effect machine having a structure located opposite a bearing surface at a variable distance therefrom; a lateral confining arrangement movable in relation to said structure and delimiting a plenum chamber designed in cooperation with said bearing surface to confine at least one cushion of pressurized fluid for supporting said machine free of said bearing surface, said lateral confining arrangement comprising a terminal part with a free end adjacent the bearing surface and separated therefrom by a certain interval; means responding to the distance between the structure and the bearing surface for displacing the terminal part of the lateral confining arrangement in relation to said structure and to said bearing surface, in a direction such that the said interval increases when said distance reduces, and conversely.
 2. A machine as claimed in claim 1, wherein the lateral confining arrangement comprises at least one deformable wall, and wherein the means responding to the distance between the structure and the bearing surface comprise a reference element fixed to said deformable wall and movable in relation to said structure in a direction substantially normal to the bearing surface, said reference element being adapted to come into contact with said bearing surface when said machine rests directly on said bearing surface.
 3. A machine as claimed in claim 2, wherein said responding means further comprises a linkage, and means on said linkage cooperating with the structure and connected to a portion of the deformable wall which is defined between the free end of said lateral cOnfining arrangement and the zone of attachment of the reference element to said deformable wall, whereby said free end is displaced when the distance between said structure and said reference element varies.
 4. A machine as claimed in claim 3, wherein the linkage comprises a lever, and said cooperating means include means fixing one end of said lever to the deformable wall and means at the other end of said lever bearing against said structure.
 5. A machine as claimed in claim 4, wherein the end of the lever which bears against the structure comprises a substantially spherical roller.
 6. A machine as claimed in claim 3, further comprising elastic means for returning the deformable wall in the direction corresponding to approach of the free end of said lateral confining arrangement towards said bearing surface.
 7. A machine as claimed in claim 6, wherein said elastic means comprise a portion of said deformable wall.
 8. A machine as claimed in claim 2, wherein the reference element comprises a runner adapted to rest upon the bearing surface, said runner having an extension upon which the structure can rest when said runner itself rests upon the bearing surface.
 9. A machine as claimed in claim 8, further comprising a stop integral with the structure, said stop including means to limit to a predetermined maximum value the distance between said structure and said runner when said machine is supported by said fluid cushion.
 10. A machine as claimed in claim 2, wherein the reference element comprises a runner having an underface adapted to rest upon the bearing surface, said machine further comprising a stop integral with the structure, said stop including means to limit to a predetermined maximum valve the distance between said structure and said runner when said machine is supported on said fluid cushion, and at least one brakeshoe having an underface located opposite the bearing surface and designed to come into contact therewith, wherein the distance between the underface of the brakeshoe and the bearing surface is smaller than the distance between the underface of the runner and said bearing surface, when said runner bears against said stop.
 11. A machine as claimed in claim 1, further comprising at least one brakeshoe located opposite the bearing surface, said brake shoe including means coming into contact with said bearing surface when said distance is reduced, an elastic means, and means securing said elastic means to said shoe and to the structure. 